This invention relates to a power apparatus in which a steerable, ground-engaging support wheel is contained within the interior of the sweep of a rotary mechanism. More particularly, this invention relates to a power apparatus such as a lawn mower, snowblower, or rotary floor brush, using such a rotary mechanism. Still more particularly, this invention relates to such an apparatus wherein the rotating mechanism is supported by at least one wheel which is mounted on a fork, a spindle portion of which is journaled within a portion of the rotating mechanism and thus within the annular area swept by the rotating mechanism. Still more particularly, this invention relates to such an apparatus in which the power apparatus includes means for adjusting the rotating mechanism as a unit, whether one or more of such rotary mechanisms are utilized, and means for individually driving the ground-engaging wheel within the rotary mechanism.
As disclosed in the applicant's copending application, mentioned above, the positioning of supporting wheels within the annual cutting blades of a lawn mower is known to the art as disclosed, for example, in U.S. Pat. Nos. 797,596, 2,121,749, 3,141,283 and 3,516,234. The latter patent discloses a steerable ground-engaging wheel located intermediate the sweep of a rotatable cutting mechanism, but, among other differences, no convenient means are provided for adjusting the height of the cutting mechanism as a unit, or for independently driving the steerable ground-engaging wheel. Moreover, only an embodiment in which a single wheel is used at the front of the vehicle is shown and multiple steerable wheels of the type described are not suggested.
Similarly, U.S. Pat. No. 3,141,283 discloses a similar type of cutting mechanism which emphasizes an arrangement in which a rotary shaft is rotatable about at least one of the supporting wheels. The supporting wheel includes a spindle rotary journaled within the rotatable member and both the rotatable member and the spindle combination are rotatably journaled within the body of the mower. In this apparatus as well, height adjustment of the cutter is inconvenient and the wheel is not driven. Furthermore, a single such wheel is used and arrays of such wheels are not suggested.
In connection with an apparatus of the type disclosed, it has been a problem in the art to provide a mechanism for conveniently raising and lowering the adjusting height of the rotary mechanism, particularly in a lawn mower embodiment. While significant advantages were obtained from the use of the concept of a journal-within-a-journal for permitting the independent rotation of the cutting blade and the steering of the supporting wheel independently from one another, adjustment of the cutting height had not been attractively convenient. The problem was magnified when considering a multiple wheel arrangement such as in a rotary brush where it might be desired to steer flexibly, linearly and laterally, such a vehicle to brush in tight corners, closely adjacent to objects, and the like. Accordingly, it is a broad aim of this invention to provide means for conveniently adjusting such a rotary mechanism as a unit, whether one or more of such mechanisms are used, in the power apparatus to a convenient height.
In addition, it is desirable in the art to provide a means for individually powering the ground-engaging steerable wheel of such an apparatus in order to provide a multiple cutting or brushing device. While certain advantages are obtained by powering the front wheels of such a device in an embodiment which uses a plurality of rearwardly fixed ground-engaging wheels, where the device includes a plurality of such rotary mechanisms, it is desirable to individually power each of the cutting wheels for steering flexibility in the device. Accordingly, it is another aim of this invention to provide a device of the type described which features individually powering each of these types of wheel assemblies.
In the patents discussed above, a single steerable ground-engaging wheel is used in conjunction with a pair of rearward ground-engaging wheels. In a number of applications, it is desirable to extend the width of the cutting or brushing path by using a plurality of rotary mechanisms, each of which is disposed about an independently steerable wheel. In many of these applications, it is further desirable to drive individually each of the independently steerable wheels. Accordingly, embodiments are disclosed which provide such capability and in which the cutting or brushing height of the rotary mechanism is conveniently adjustable. Moreover, all of the wheels of the vehicle, preferably in a three-wheel embodiment, can comprise suitable wheels with the feature mentioned above. In the alternative, one or more steerable wheels can be located in either the forward or rearward portion of the vehicle.
Still further, and in another embodiment of the basic invention, it is desired to provide a canted or sloped caster to such an arrangement while permitting the free rotation of the mechanism.
Accordingly, it is a broad objective of this invention to provide a device of the type described having the additional features and capabilities of unitary height adjustment, and individually powering the steerable ground-engaging wheel.
These and other advantages will become apparent from the detailed description of the invention taken in conjunction with the accompanying drawings.